1. Field of the Invention
The present invention relates generally to footwear and more particularly to athletic footwear including a hard grind plate embedded in a shoe for riding longitudinally along rails, pipes and the like.
2. Description of the Prior Art
Athletic footwear has gained immense popularity in the United States and throughout the world to be worn during exercise activities. Athletic footwear is known incorporating hard soles often used in bowling activity and to mount cleats used in baseball or softball athletic contests. Other athletics prefer shoes with cushioned soles such as in the case tennis shoes or basketball shoes.
Other athletic or entertainment activity which has gained immense popularity in recent years is skateboarding and in-line roller skating. Highly athletic youthful participants have developed a maneuver commonly referred to as grinding wherein the athlete will jump into the air while riding a skateboard or wearing a pair of in-line skates and slide the undercarriage along an elongated track defined by, for instance, a hand rail, park bench back or curb edge. This activity is referred to in the sport as "grinding".
Grinding shoes have been proposed which incorporate a hard plate in the arch area or other strategic location on the sole of the shoe with a downwardly opening cylindrical trough so the wearer can wear the shoe in a normal manner and, when the opportunity presents itself for a grinding activity, he or she can run toward a rail, curb or the like and leap upwardly mounting the sliding surface with the hard plate to be centered in said trough to slide therealong. This activity has gained great popularity in the field and is currently enjoyed by many youngsters utilizing shoes marketed under the trademark SOAP by the assignee of the present application. Such shoes incorporate grind plates of the type disclosed in U.S. patent application Ser. No. 08/890,595 filed Jun. 9, 1997, U.S. patent application Ser. No. 08/799,062, filed Feb. 10, 1997, claiming priority of Provisional Application Ser. No. 60/022,318, filed Jul. 23, 1996 all assigned to the assignee of the present application, such applications now having been granted U.S. Patent Nos. 6,006,451 and 5,970,631.
Grind plates incorporated in the SOAP shoes are typically constructed with a saddle configuration to provide a downwardly open semi-cylindrical trough having a transverse upper extent projecting horizontally throughout a majority of the shoe width to serve as a low friction bearing surface for sliding along the underlying rail, curb or the like. Such devices, while having enjoyed significant commercial success, suffer two major shortcomings. First, the substantially horizontally projecting upward extent of the trough does not truly reflect the ideal surface curvature in the lateral direction for accommodating the variations in angular orientations of the shoe necessary to accommodate the ideal foot manipulations necessary to allow for the wearer to exercise the maneuvers preferred by a high percentage of the participating athletes. I have discovered that, while each athlete may have his or her own preferred unique grinding exercises or characteristics, the majority of the grinding population tend to, in a typical grinding maneuver, manipulate the foot through a predictable range, as an example, because of the human anatomy and balance necessary for a successful and enjoyable maneuver, the bearing surface of the grind plate must typically accommodate a more gradual laterally outward rolling action than is necessary for rolling the shoe over in the medial direction. Thus, their exists a need for a grinding plate which while providing a stable flat support when the shoe is erect but which will allow for a rolling action when angled in either transverse direction and will provide a relatively free rolling action in the lateral direction.
Another shortcoming addressed by the plate of the present invention is the fact that the prior plates are themselves somewhat heavy, particularly when incorporated in shoes worn throughout the day on successive days by youngsters involved in the numerous high energy activities typically associated with youth. Thus, there exists a need for a grind plate having a relatively light weight structure configured with downwardly facing grind surfaces only in the strategical locations necessary to support expected grinding maneuvers executed by the wearers.